Shirt collar



FIG. 1 is a front right perspective view of a shirt collar;

FIG. 2 is a front left perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a right elevation view thereof;

FIG. 5 is a back elevation view thereof; and,

FIG. 6 is a top plan view thereof.

The broken lines shown in the drawings depict portions of a shirt that form no part of the claimed invention. 

CLAIM The ornamental design for a shirt collar, as shown and described. 